TWI633173B - Liquid crystal composition and liquid crystal display element - Google Patents

Abstract

The present invention discloses a liquid crystal composition comprising one or more compounds of formula I, one or more compounds of formula II and a compound of formula II-A:

Each of these substituents gives its definition.

The composition provided by the invention has low viscosity γ ₁ , moderate dielectric anisotropy Δ ε, moderate optical anisotropy Δn, and can achieve rapid response of liquid crystal display.

Description

Liquid crystal composition and liquid crystal display element

The present invention relates to the field of liquid crystal display, and in particular to a liquid crystal composition and a liquid crystal display element or liquid crystal display comprising the liquid crystal composition.

At present, the application range of liquid crystal compounds is expanding wider and wider, and it can be applied to various types of displays, electro-optical elements, sensors, and the like. There are many kinds of liquid crystal compounds used in the above display field, and nematic liquid crystals are most widely used. Nematic liquid crystals have been used in passive TN, STN matrix displays and systems with TFT active matrices.

For the application of thin film transistor technology (TFT-LCD), although the market has been very large in recent years, and the technology has gradually matured, people's requirements for display technology are also constantly improving, especially in achieving rapid response and reducing the driving voltage. Reduce power consumption and other aspects. As one of the important optoelectronic materials for liquid crystal displays, liquid crystal materials play an important role in improving the performance of liquid crystal displays.

As a liquid crystal material, it is required to have good chemical and thermal stability as well as stability against electric fields and electromagnetic radiation. As a liquid crystal material for thin film transistor technology (TFT-LCD), it is not only required to have the above stability, but also has a wide nematic temperature range, a suitable birefringence anisotropy, a very high resistivity, Good UV resistance, high charge retention and low vapor pressure.

For the dynamic picture display application, eliminating the image sticking and smearing, the liquid crystal is required to have a fast response speed, so the liquid crystal is required to have a low rotational viscosity γ ₁ ; in addition, for the portable device, in order to reduce the energy consumption of the device, It is desirable that the driving voltage of the liquid crystal be as low as possible; and for a display such as a television, the driving voltage requirement for the liquid crystal is not so low.

The viscosity of the liquid crystal compound, especially the rotational viscosity γ ₁ directly affects the response time after the liquid crystal is powered on, whether it is the rise time (t _on ) or the fall time (t _off ), which is proportional to the rotational viscosity γ ₁ of the liquid crystal, and rises. The time (t _on ) is related to the liquid crystal cell and the driving voltage, and can be adjusted by increasing the driving voltage and reducing the thickness of the liquid crystal cell; and the falling time (t _off ) is independent of the driving voltage, mainly the elastic constant of the liquid crystal. In relation to the thickness of the liquid crystal cell, the decrease in thickness reduces the fall time (t _off ), while in different display modes, the liquid crystal molecules move in different ways. The three modes of TN, IPS, and VA are respectively the average elastic constant K, the torsional elastic constant, The bending elastic constant is inversely proportional.

According to the theory of liquid crystal continuum, after different kinds of liquid crystals are deformed by external force (electric field, magnetic field), they will "rebound" back to the original shape by interaction between molecules; similarly, liquid crystal is also due to intermolecular The interaction forces form a "viscosity." Small changes in liquid crystal molecules can cause significant changes in the performance of liquid crystals. Some of these changes are regular, and some seem to be difficult to find. They also have a significant impact on the interaction between liquid crystal molecules. These effects are very Subtle, so far has not formed a perfect theoretical explanation.

The viscosity of liquid crystals is related to the molecular structure of liquid crystals. It is one of the important tasks of liquid crystal formulators to study the relationship between the viscosity of liquid crystal systems formed by different liquid crystal molecules and the molecular structure of liquid crystals.

An object of the present invention is to provide a liquid crystal composition and a liquid crystal display element or liquid crystal display comprising the liquid crystal composition, which has a low viscosity, can achieve a fast response, and has a moderate dielectric anisotropy Δ ε Moderate optical anisotropy Δn, high stability to heat and light. A liquid crystal display element or liquid crystal display comprising the liquid crystal composition has a wide nematic temperature range, suitable birefringence anisotropy, very high resistivity, good ultraviolet resistance, high charge retention, and low steam Pressure and other properties.

In order to achieve the above technical effects, the present invention provides a liquid crystal composition. The liquid crystal composition provided by the present invention comprises one or more compounds of the formula I, one or more compounds of the formula II-A of the formula II: Wherein Y ₁ represents F, OCF ₃ , CF ₃ or OCF ₂ H; and R ₁ , R ₂ and R ₃ each independently represent an alkyl group having 1 to 9 carbon atoms, and the fluorine-substituted carbon atom is 1 to 9 An alkyl group, an alkoxy group having 1 to 9 carbon atoms, a fluorine-substituted alkoxy group having 1 to 9 carbon atoms, an alkenyl group having 2 to 9 carbon atoms, and a fluorine-substituted carbon atom; An alkenyl group of 2-9, an alkenyloxy group having 3 to 8 carbon atoms or an alkenyloxy group having 3 to 8 carbon atoms; Represents 1,4-phenylene, 1,4-cyclohexylene or 1,4-cyclohexylene.

The liquid crystal composition provided by the present invention must contain at least one compound of the formula I, and must contain a compound of the formula II-A in the compound of the formula II, and may further comprise one or more compounds of the formula II in addition to the formula II- Other compounds than A.

As a preferred embodiment, the liquid crystal composition provided by the present invention does not contain a liquid crystal compound containing -CN, and does not contain a liquid crystal compound containing a pyridine or pyrimidine ring.

The present invention is further preferably a liquid crystal compound which does not contain a fused ring structure.

The liquid crystal composition provided by the invention has Δn [589 nm, 25 ° C] > 0.08, Δ ε [1 KHz, 25 ° C] > 2, clear point Cp > 70.0 ° C, and rotational viscosity γ ₁ [25 ° C] at 40 ~ 110 mPa. Between s.

The liquid crystal composition provided by the present invention, wherein the compound of the formula I is preferably a mass content of 1 to 20%; the compound of the formula II-A is preferably a content of 20 to 40%, and the compound of the formula II is preferably. The content is 25-60%.

-CN has a large permanent dipole moment, the electron cloud is rich, easy to adsorb cations and lead to the decline of liquid crystal electrical properties, such as charge retention rate VHR, resistivity ρ, power consumption, etc.; pyridine, pyrimidine ring compounds due to UV Electrons are prone to excitation and cause quality degradation.

The liquid crystal molecules of the fused ring structure often do not have good linearity and the viscosity is too large, and the inclusion of these components is not conducive to improving the response speed of the liquid crystal.

The compound of formula I is preferably a compound of formula I 1-I 4 : Wherein, R ₁ each independently represent an alkyl group having 1-9 carbon atoms, carbon atoms, fluorine-substituted alkyl group having 1-9 carbon atoms, alkoxy having 1-9, carbon atoms, fluorine-substituted Alkoxy groups having a number of 1-9, alkenyl groups having 2 to 9 carbon atoms, alkenyl groups having 2 to 9 carbon atoms substituted by fluorine, alkenyloxy groups having 3 to 8 carbon atoms or Fluorine substituted alkenyloxy group having 3-8 carbon atoms; the compound of formula II comprises a compound of formula II-A and preferably one or more compounds comprising a compound of II 1-II 10 :

The compounds of formula I generally have good miscibility with other liquid crystals, and have a high clear point CP, generally above 200 ° C, but vary with the length of the R ₁ alkyl chain, and the alkyl chain is longer, clear point CP will be higher, a change will change Y ₁ CP, while the dielectric anisotropy △ ε changes, OCF ₃ CP will bring increased with respect to the rising above about 10 deg.] C and a dielectric anisotropy △ ε F of .

The dielectric anisotropy Δε of the compound of formula I is large, between 4-13, due to the electronegativity of the substituents OCF ₃ and CF ₃ and the cumulative effect with the fluorine atom, I 3 , I 1 The compound exhibits a large permanent dipole moment, and thus the dielectric anisotropy Δε is relatively large, reaching 8 or more.

The compound of formula I 1-I 4 has a terphenyl conjugated system, and the compound shown has a large optical anisotropy Δn, and I 1 and I 4 have a larger Δn due to the oxygen atom participating in the conjugation. Suitable for blending larger Δn liquid crystal mixtures.

The compound represented by the formula II-A has an especially low rotational viscosity γ ₁ , a near-neutral dielectric anisotropy Δ ε , and a small optical anisotropy Δ n , which is advantageous in improving liquid crystal viscosity and low temperature performance.

The different alkyl substituents of the compound of formula II have an effect on the rotational viscosity γ ₁ of the liquid crystal and the clear point CP. Generally, the longer alkyl chain or alkenyl chain increases the rotational viscosity γ _{1 of the} liquid crystal while improving the clarity. Point CP, but γ _{1 is} higher than the compound of formula II-A.

The liquid crystal composition provided by the present invention may further comprise one or more compounds represented by formula III.

Wherein, R ₄ represents an alkyl group having 1-9 carbon atoms, carbon atoms, fluorine-substituted alkyl group having 1-9 carbon atoms, an alkoxy group having 1-9 carbon atoms is substituted with fluorine 1 Alkoxy group of -9, alkenyl group having 2 to 9 carbon atoms, alkenyl group having 2 to 9 carbon atoms substituted by fluorine, alkenyloxy group having 3 to 8 carbon atoms or fluorine substituted An alkenyloxy group having 3 to 8 carbon atoms; Represents 1,4-phenylene, 1,4-cyclohexylene or 1,4-cyclohexylene.

The liquid crystal composition provided by the present invention, wherein the compound of the formula III is preferably present in an amount of from 5 to 20% by mass.

The compound of formula III is specifically preferably:

The compound of formula III has optical anisotropy Δn moderate, dielectric anisotropy △ ε is between 5-9, lower rotational viscosity γ ₁ , clear point CP is generally above 120 ° C, can be used to adjust mixed liquid crystal CP , △n, △ε, γ ₁ and other parameters. In the compound of formula Ⅲ, preferably a straight chain alkyl compound C ₁ -C ₅ represented by R _1.

In the liquid crystal composition provided by the present invention, one or more compounds of the formula IV may also be added:

Wherein R ₅ represents an alkyl group having 1 to 9 carbon atoms, a fluorine-substituted alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, and a fluorine-substituted carbon atom of 1 Alkoxy group of -9, alkenyl group having 2 to 9 carbon atoms, alkenyl group having 2 to 9 carbon atoms substituted by fluorine, alkenyloxy group having 3 to 8 carbon atoms or fluorine substituted An alkenyloxy group having 3 to 8 carbon atoms; n represents 0 or 1; and (F) represents H or F.

The liquid crystal composition provided by the present invention, wherein the compound of the formula IV is preferably present in an amount of from 5 to 20% by mass.

Among the compounds of the formula IV, a compound wherein R ₁ represents a C ₁ -C ₅ linear alkyl group is preferred. The compound of formula IV has a moderate Δ ε, a high CP, and a low viscosity is suitable for adjusting the viscosity, CP, Δ ε of the liquid crystal.

Further preferred compounds of formula IV are:

The liquid crystal composition provided by the present invention may further comprise one or more compounds represented by the formula V: Wherein R ₆ and R ₇ each independently represent an alkyl group having 1 to 9 carbon atoms, a fluorine-substituted alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, or a fluorine substitution. An alkoxy group having 1 to 9 carbon atoms, an alkenyl group having 2 to 9 carbon atoms, an alkenyl group having 2 to 9 carbon atoms substituted by fluorine, and an alkene having 3 to 8 carbon atoms An oxy or fluoro substituted alkenyloxy group having 3-8 carbon atoms; Y ₃ and Y ₄ represent H or F, but not simultaneously F; Represents 1,4-phenylene, 1,4-cyclohexylene or 1,4-cyclohexylene.

The liquid crystal composition of the present invention, wherein the compound of the formula V is preferably present in an amount of from 2 to 15% by mass.

The compound of the formula V is preferably a compound wherein R ₆ and R ₇ represent a C ₁ - C ₅ linear alkyl group. The compound of the formula V has a high CP, which is advantageous for expanding the temperature range of use of the liquid crystal.

Further preferred compounds of formula V are:

The compounds R ₆ and R ₇ represented by the formula V are preferably a C ₁ - C ₅ linear alkyl group.

The liquid crystal composition provided by the present invention may further comprise one or more compounds represented by the formula VI. Wherein R ₈ represents an alkyl group having 1 to 9 carbon atoms, a fluorine-substituted alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, and a fluorine-substituted carbon atom of 1 Alkoxy group of -9, alkenyl group having 2 to 9 carbon atoms, alkenyl group having 2 to 9 carbon atoms substituted by fluorine, alkenyloxy group having 3 to 8 carbon atoms or fluorine substituted An alkenyloxy group having 3 to 8 carbon atoms; Represents 1,4-phenylene, 1,4-cyclohexylene or 1,4-cyclohexylene; Represents 1,4-phenylene, fluoro1,4-phenylene, 1,4-cyclohexylene or 1,4-cyclohexylene; R _{9 is} selected from F, and the number of carbon atoms is 1-9 An alkyl group, a fluorine-substituted alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, a fluorine-substituted alkoxy group having 1 to 9 carbon atoms, and 2 carbon atoms An alkenyl group of -9, an alkenyl group having 2 to 9 carbon atoms substituted by fluorine, an alkenyloxy group having 3 to 8 carbon atoms or an alkenyloxy group having 3 to 8 carbon atoms substituted by fluorine .

The liquid crystal composition provided by the present invention, wherein the compound of the formula VI is preferably present in an amount of from 5 to 30% by mass.

Further preferred compounds of formula VI are:

The compounds represented by formulas VI-1 and VI-2 are dielectric anisotropy Δε close to neutral, low rotational viscosity γ ₁ , high clear point, large K value, can be used to formulate liquid crystal K value and γ ₁ to achieve a quick response. The compound represented by the terphenyl group VI-5 has a large optical anisotropy Δn due to its large conjugated system, and is particularly suitable for mixing a liquid crystal having a large refractive index.

The liquid crystal composition provided by the present invention may further be added with one or more compounds represented by VII.

Wherein R ₁₀ represents an alkyl group having 1 to 9 carbon atoms, a fluorine-substituted alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, and a fluorine-substituted carbon atom of 1 Alkoxy group of -9, alkenyl group having 2 to 9 carbon atoms, alkenyl group having 2 to 9 carbon atoms substituted by fluorine, alkenyloxy group having 3 to 8 carbon atoms or fluorine substituted An alkenyloxy group having 3 to 8 carbon atoms; An 1,4-phenylene group, a fluorinated 1,4-phenylene group, a 1,4-cyclohexylene group, a 1,4-cyclohexylene group, and/or a 1,4-cyclohexylene group. One or more of the groups formed by the unsubstituted two CH ₂ being replaced by oxygen; p represents 2 or 3.

The liquid crystal composition of the present invention, wherein the compound of the formula VII is preferably present in an amount of from 5 to 55% by mass.

Further preferred compounds of formula VII are:

The compound of the formula VII has a large dielectric anisotropy Δ ε and a low rotational viscosity γ ₁ , which can be used for formulating a liquid crystal mixture for lowering the liquid crystal driving voltage and accelerating the response speed of the display element.

The liquid crystal composition provided by the present invention may further comprise one or more formulas VIII-1 and VIII-2, with or without the compound of formula III, formula IV, formula V, formula VI and formula VII. And/or a cycloalkyl-containing compound represented by VIII-3 among them, Each independently represents a group formed by one or two unsubstituted CH ₂ 1,4-cyclohexylene groups substituted by O, 1,4-phenylene and/or fluoro One or more of 1,4-phenylene groups; Z ₁ , Z ₂ , and Z ₃ each independently represent a single bond, -CF ₂ O- or -CH ₂ O-; m, k, and g are each independently represented 1, 2 or 3; i represents 0, 1 or 2; R ₁₁ represents F, an alkyl group having 1 to 9 carbon atoms, a fluorine-substituted alkyl group having 1 to 9 carbon atoms, and 1 to 1 carbon atom 9 alkoxy group, fluorine-substituted alkoxy group having 1-9 carbon atoms, alkenyl group having 2 to 9 carbon atoms, alkenyl group having 2 to 9 carbon atoms substituted by fluorine, carbon atom An alkenyloxy group having 3-8: or an alkenyloxy group having 3 to 8 carbon atoms; R ₁₂ represents an alkyl group having 1 to 5 carbon atoms, and a fluorine-substituted carbon atom is 1 - An alkyl group of 5, an alkoxy group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms substituted by fluorine, an alkenyl group having 2 to 5 carbon atoms, and a fluorine-substituted carbon atom An alkenyl group of 2 to 5, an alkenyloxy group having 3 to 5 carbon atoms or an alkenyloxy group having 3 to 5 carbon atoms substituted by fluorine.

The compound of the formula VIII does not contain a soft terminal alkyl chain, and thus has a strong rigidity, and the relative action between the liquid crystal molecules changes, exhibiting a large K value and a high CP.

The compound of VIII-1 is preferably: The compound of VIII-2 is preferably: The compound of VIII-3 is preferably:

The different ratios of the components of the liquid crystal composition may exhibit slightly different properties, such as dielectric anisotropy Δ ε, optical anisotropy Δn, conversion of nematic type of liquid crystal to liquid transition temperature point CP, low temperature Stability will vary and can be applied to different types of display elements, but the same feature is lower rotational viscosity γ ₁ . Applied to liquid crystal display elements for fast response.

The liquid crystal compound provided by the invention may also be added with dopants of various functions, and the dopant content is preferably between 0.01 and 1%. These dopants are mainly antioxidants, ultraviolet absorbers, and chiral agents.

The antioxidant and the ultraviolet absorber are preferably: S represents an integer of 1-10.

The chiral agent is preferably (left-handed or right-handed):

The invention further relates to a liquid crystal display element or liquid crystal display comprising any of the liquid crystal compositions described above; the display element or display being an active matrix display element or display or a passive matrix display element or display.

The liquid crystal display element or liquid crystal display is preferably an active matrix addressed liquid crystal display element or a liquid crystal display.

The active matrix display element or display is specifically a TN-TFT or IPS-TFT liquid crystal display element or display.

The liquid crystal composition provided by the invention has low viscosity and can achieve fast response, and has moderate dielectric anisotropy Δ ε, moderate optical anisotropy Δn, high stability against heat and light.

The liquid crystal material comprising the liquid crystal composition provided by the present invention not only has good chemical and thermal stability and stability against electric fields and electromagnetic radiation. Moreover, as a liquid crystal material for thin film transistor technology (TFT-LCD), it also has a wide nematic temperature range, suitable birefringence anisotropy, very high resistivity, good ultraviolet resistance, and high charge. Maintainability and low vapor pressure.

The invention is further illustrated by the following specific examples, but the invention is not limited to the following examples. The above methods are conventional methods unless otherwise specified. The raw materials can be obtained from an open commercial route unless otherwise specified. Percentages are percentages by mass unless otherwise stated.

In the following examples, CP indicates a sharp point and was directly measured using a WRX-1S micro-thermal analyzer, and the heating rate was set to 3 ° C / min.

△ n represents anisotropic optical (589nm, 20 ℃), △ ε represents the anisotropy of dielectric (25 ℃, 1KHz, HP4284A, 5.2 micron TN left box), γ ₁ denotes the rotational viscosity (mPas) when 20 ℃, VHR (%) represents charge retention (5V, 60Hz, 20°C), ρ(×10 ¹³ Ω.cm) represents resistivity (20°C) voltage retention rate VHR(%) of the tester and resistivity ρ(×10 ¹³ Ω.cm) are TOYO06254 and TOYO6517 liquid crystal physical property evaluation systems (test temperature 20 ° C, time 16 ms, test box 7.0 microns)

Example 1

Monomer content (%)

△ ε [1 KHz, 20 ° C]: 9.0

△n[589nm, 20°C]: 0.125

Cp: 118 ° C

γ ₁ : 158 mPa.s.

Example 2

△ ε [1KHz, 20 ° C]: 4.2

△n[589nm, 20°C]: 0.104

Cp: 130 ° C

γ ₁ : 175 mPa.s.

Example 3

△ ε [1 KHz, 20 ° C]: 9.9

△n[589nm, 20°C]: 0.116

Cp: 79 ° C

γ ₁ : 77 mPa.s.

Example 4

△ ε [1 KHz, 20 ° C]: 8.7

△n[589nm, 20°C]: 0.106

Cp: 99 ° C

γ ₁ : 98 mPa.s.

Example 5

△ ε [1 KHz, 20 ° C]: 9.0

△n[589nm, 20°C]: 0.155

Cp: 104 ° C

γ ₁ : 112 mPa.s.

Example 6

△ ε [1KHz, 20 ° C]: 5.6

△n[589nm, 20°C]: 0.109

Cp: 112 ° C

γ ₁ : 121 mPa.s.

Example 7

△ ε [1KHz, 20 ° C]: 4.2

△n[589nm, 20°C]: 0.14

Cp: 143 ° C

γ ₁ : 280 mPa·s.

It can be seen from the above examples that the liquid crystal composition of the present invention has a low rotational viscosity γ ₁ for liquid crystal display and can achieve a fast response. It is especially suitable for liquid crystal materials for TN and IPS modes.

Claims (9)

A liquid crystal composition comprising one or more compounds of formula I, one or more compounds of formula II, and a compound of formula II-A: Wherein Y ₁ represents F; R ₁ , R ₂ and R ₃ each independently represent an alkyl group having 1 to 9 carbon atoms, a fluorine-substituted alkyl group having 1 to 9 carbon atoms, and 1 to 1 carbon atom. 9 alkoxy group, fluorine-substituted alkoxy group having 1-9 carbon atoms, alkenyl group having 2 to 9 carbon atoms, alkenyl group having 2 to 9 carbon atoms substituted by fluorine, carbon atom An alkenyloxy group having 3-8: or an alkenyloxy group having 3 to 8 carbon atoms; Represents 1,4-phenylene, 1,4-cyclohexylene or 1,4-cyclohexylene; the liquid crystal composition further comprises one or more compounds of the formula VII: Wherein R ₁₀ represents an alkyl group having 1 to 9 carbon atoms, a fluorine-substituted alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, and a fluorine-substituted carbon atom of 1 Alkoxy group of -9, alkenyl group having 2 to 9 carbon atoms, alkenyl group having 2 to 9 carbon atoms substituted by fluorine, alkenyloxy group having 3 to 8 carbon atoms or fluorine substituted An alkenyloxy group having 3 to 8 carbon atoms; An 1,4-phenylene group, a fluorinated 1,4-phenylene group, a 1,4-cyclohexylene group, a 1,4-cyclohexylene group, and/or a 1,4-cyclohexylene group. One or more of the groups formed by the unsubstituted two CH ₂ being replaced by oxygen; p represents 2 or 3. The liquid crystal composition according to claim 1, wherein the one or more compounds of the formula I are one or more of the compounds of the formula I1 to IV: Wherein R ₁ each independently represents an alkyl group having ₁ to 9 carbon atoms, a fluorine-substituted alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, or a fluorine-substituted carbon atom; Alkoxy groups having a number of 1-9, alkenyl groups having 2 to 9 carbon atoms, alkenyl groups having 2 to 9 carbon atoms substituted by fluorine, alkenyloxy groups having 3 to 8 carbon atoms or Fluorine substituted alkenyloxy group having 3-8 carbon atoms; the one or more compounds of formula II comprising one or more compounds of the compounds of formula II 1 to formula II: The liquid crystal composition according to claim 1 or 2, wherein the liquid crystal composition further comprises one or more compounds of the formula III: Wherein R ₄ represents an alkyl group having 1 to 9 carbon atoms, a fluorine-substituted alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, and a fluorine-substituted carbon atom of 1 Alkoxy group of -9, alkenyl group having 2 to 9 carbon atoms, alkenyl group having 2 to 9 carbon atoms substituted by fluorine, alkenyloxy group having 3 to 8 carbon atoms or fluorine substituted An alkenyloxy group having 3 to 8 carbon atoms; Represents 1,4-phenylene, 1,4-cyclohexylene or 1,4-cyclohexylene. The liquid crystal composition according to claim 1 or 2, wherein the liquid crystal composition further comprises one or more compounds of the formula IV: Wherein R ₅ represents an alkyl group having 1 to 9 carbon atoms, a fluorine-substituted alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, and a fluorine-substituted carbon atom of 1 Alkoxy group of -9, alkenyl group having 2 to 9 carbon atoms, alkenyl group having 2 to 9 carbon atoms substituted by fluorine, alkenyloxy group having 3 to 8 carbon atoms or fluorine substituted An alkenyloxy group having 3 to 8 carbon atoms; n represents 0 or 1; and (F) represents H or F. The liquid crystal composition according to claim 1 or 2, wherein the liquid crystal composition further comprises one or more compounds represented by the formula V: Wherein R ₆ and R ₇ each independently represent an alkyl group having 1 to 9 carbon atoms, a fluorine-substituted alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, or a fluorine substitution. An alkoxy group having 1 to 9 carbon atoms, an alkenyl group having 2 to 9 carbon atoms, an alkenyl group having 2 to 9 carbon atoms substituted by fluorine, and an alkene having 3 to 8 carbon atoms An oxy or fluoro substituted alkenyloxy group having 3-8 carbon atoms; Y ₃ and Y ₄ represent H or F, but not simultaneously F; Represents 1,4-phenylene, 1,4-cyclohexylene or 1,4-cyclohexylene. The liquid crystal composition according to claim 1 or 2, wherein the liquid crystal mixture further comprises one or more compounds of the formula VI: Wherein R ₈ represents an alkyl group having 1 to 9 carbon atoms, a fluorine-substituted alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, and a fluorine-substituted carbon atom of 1 Alkoxy group of -9, alkenyl group having 2 to 9 carbon atoms, alkenyl group having 2 to 9 carbon atoms substituted by fluorine, alkenyloxy group having 3 to 8 carbon atoms or fluorine substituted An alkenyloxy group having 3 to 8 carbon atoms; Represents 1,4-phenylene, 1,4-cyclohexylene or 1,4-cyclohexylene; Represents 1,4-phenylene, fluoro1,4-phenylene, 1,4-cyclohexylene or 1,4-cyclohexylene; R ₉ represents F, and the number of carbon atoms is 1-9 An alkyl group, a fluorine-substituted alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, a fluorine-substituted alkoxy group having 1 to 9 carbon atoms, and 2 to 2 carbon atoms The alkenyl group of 9 and the fluorine-substituted alkenyl group having 2 to 9 carbon atoms, the alkenyloxy group having 3 to 8 carbon atoms or the alkenyloxy group having 3 to 8 carbon atoms substituted by fluorine. The liquid crystal composition according to claim 1 or 2, wherein the liquid crystal composition further comprises one or more compounds represented by the formula VIII-1, one or more compounds represented by the formula VIII-2 and/or Or one or more compounds of formula VIII-3: among them, Each independently represents a group formed by 1,4-cyclohexylene, 1,4-cyclohexylene, or one or two unsubstituted CH ₂ substituted by oxygen, 1,4-phenylene and/or fluoro One or more of 1,4-phenylene groups; Z ₁ , Z ₂ , and Z ₃ each independently represent a single bond, -CF ₂ O- or -CH ₂ O-; m, k, and g are each independently represented 1, 2 or 3; i represents 0, 1 or 2; R ₁₁ represents F, an alkyl group having 1 to 9 carbon atoms, a fluorine-substituted alkyl group having 1 to 9 carbon atoms, and 1 to 1 carbon atom; 9 alkoxy group, fluorine-substituted alkoxy group having 1-9 carbon atoms, alkenyl group having 2 to 9 carbon atoms, alkenyl group having 2 to 9 carbon atoms substituted by fluorine, carbon atom An alkenyloxy group having 3-8: or an alkenyloxy group having 3 to 8 carbon atoms; R ₁₂ represents an alkyl group having 1 to 5 carbon atoms, and a fluorine-substituted carbon atom is 1 - An alkyl group of 5, an alkoxy group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms substituted by fluorine, an alkenyl group having 2 to 5 carbon atoms, and a fluorine-substituted carbon atom An alkenyl group of 2 to 5, an alkenyloxy group having 3 to 5 carbon atoms or an alkenyloxy group having 3 to 5 carbon atoms substituted by fluorine. A liquid crystal display element comprising the liquid crystal composition according to any one of claims 1 to 7, wherein the liquid crystal display element is an active matrix display element or a passive matrix display element. The liquid crystal display device of claim 8, wherein the active matrix display element is a TN-TFT or an IPS-TFT liquid crystal display element.